Retractable landing gear



Dec. .1, 1925. Q

1,563,384 G. C. LOENING RETRACTABLE LANDING GEAR Filed Feb. 16, 1925 5 Sheets-Sheet 1 INVENTOR I l WK L h:

A TTORNEY Dec. l, 1925- G. C. LOENING RETRACTABLE LANDING GER Filed Feb. 1e, 1925 5 Sheets-Sheet 2 www /N VE N TOI? A TTU/MEV Dec. 1, 1925- G. c. LoENlNG RETRACTABLE LANDING GEAR Filed Feb. 16, 1925V 5 Sheets-Sheet I3 Dec. 1 1925- G. C. LOENING RETRACTABLE LANDING' GEAR Filed Feb. 16, 1925 5 Sheets-Sheet 4 'A'TToRNEr Dec# 1, 1925 1,563,384

G. vc. LOENING RETRAG TABLE LANDING GEAR Filed Feb. 1e, 1925 v 5 sheets-sheet s Afro/mfr Patented Dec.v 1, 1925.

UNITED "s'rA'rEs GBOVER C. LOENING, F NEW YORK, N. Y.l

BETRACTABLE LANDING GEAR.

` .Application led February 16, 1925. Serial No. 9,387.

To all whom it may concer/n.:

Be it known that I, Guovan C. LoENING, a. citizen of the United States, and resident of New York city, in the countyl and State of New York, have invented a new and useful Retractable Landing Gear, of which the following is a specification.

The invention relates to retractable or folding landing-gears for iiying machines, and more partlcularly for'amphibian machines or iying-boats. The object is to provide a simple, strong, compact, and readily operated landing-gear for such purposes, and a special construction of the hull body to accommodate operating devices for the landing-gear in its lower portion and to receive the wheels folded.. downward into pockets opening through the upper sides or sponsons of such hull portion. The inven tion may be said to comprise the parts, improvements and combinations hereinafter described and more particularly pointed out in the claims.`

In the accompanying drawings forming part hereof:

Fig. 1 is a side elevation of the forward part of an amphibian iiying-boatshowing the landing-gear unfolded or projected for alighting on land or deck;

Fig. 2 is a transversey vertical section on a larger scale, taken on thev line 2 2 of Fig. 1;

Fig. 3 is a fragmentary transverse vertical section on the line 3 3 vof Fig. 1;

Fig. 4 is a detail transverse vertical sec-v tion on a still larger scale, taken on the line Fig. 5 is a section on the line 5 5 of Fig. 4; Y

Fig. 6 is an enlarged vertical transverse section showing one slde of the landing-gear in projected position;

Fig. 7 is a vertical section through the wheel on the line 7 7 of Fig. 6;

Fig. 8 is a schematic view illustrating the projected and retracted positions of the lanciing gea-r in full and broken lines, respectively, and with the reversible electric driving motor and the automatic cut-out removed upward from their positions and arranged in an electrical diagram with the circuits and the operators control; and

Fig. 9 is a section on the line 9 9 of Fig. 2.

The body of the machine comprises an upper portlon 1 anda lower, hull portion 2,

preferably of unit construction. The hull portion 2 has lateral extensions or sponsons 3, which are utilized to provide downwardly entering pockets 4 whereinV the wheels 5,

when folded, are largely absorbed into the hull, both to get them out ofthe way so that the machine may alight u on water and to reduce headresistance w en vin flight.

The construction is such, also, that the folding members 6, 7, which project from the body when the landing-gear is unfolded are substantially entirely received within the l lines of the hull when folded. The members Y 6, 7 may be referred to as linkage.

The lower boat or ioat portionsv 2 of the body is made with a transverse opening or` gallery 8 intersecting the wheel-pockets, this Igallery being formed between two bulkheads 9, 10, which, together with the inner covering 11 of the pockets, wall ofi' the gallery and the pockets from the buoyant interior of the hull. The ends of the gallery open throughthe sides of the hull, which are slotted fromtlie chine corners 12 to the regions of the junctions between the portions 1 and 2; and the bottom of the gallery is bridged across by the V-bottom 13 of the boat. The wheel-,pockets 4 are somewhat more than semi-circular, and extend obliquely downward and inward from the upper sides of the sponson enlargements 3 of the hull, cutting into the bulkheads 9, 10. The slotted entrances of the pockets lie in the direction of thelength of the hull, so as to receive the wheels which are mounted to swing laterally of the hull, upward, inward, and downward into the pockets for folding, and upward, outward, and downward for unfolding. Frame members 14, 15, 16, incor- )porated between the walls of the bulkheads, form part of the structural framework of the hull, longitudinal members of which crossing the'gallery are represented at 17, 18.

The two wheels 5 are carried by hinged members 6, which are pivoted to fittings 19, at the chine corners, that is to say the lower, outer corners of the boat, on axes which are substantially parallel with the length of the boat. The fittings 19 are on the ends nof transverse metal members 20, which are riveted to the transverse frame members 16 of the bulkheads. The hull with its lateral sponsons and its internal structural elements are utilized toformas much as possible yof the frame of the landing-gear, givlng a wide tread span between the wheels when in position for landing, withcomparatively short folding members,as is apparent in Fig. '2.

The members 6 are shown of triangular construction, comprising, each, a double strutelement 21, which extends downward and outward from the hinge to the l1ead22 of the member, in theunfolded or operative position of the gear, a horn 23 extending upward from the head at the inner side 0f the Wheel, and a double brace l24 extending from the hinge to the top of the horn. y

The members 6 are sustained inthe operative position, and are folded and unfolded, through and by means ofmovable struts or links 7. These are`pivoted at their lower, or outer. ends, at 25, to the upper, outer corners of the members 6, and at their upper, or inner ends, at26, to travelers 27. The members 6 are braced against rearward stress in landing by bifurcated stay members 28, whichare connected at their rear ends to the heads 22 and are pivoted at their forward enols onlongitudinal axes to fittings 29 on the chines. The travelers 27 are operated by devices in the `gallery 8, in the form of screw-shafts 30, the threads of which are of self-holding pitch. These screw-shaftsone for each side of the landing-gear, lie diagonally in crossing relation in transverse planes, having theirupper ends adjacent the upper ends of the slotted entrances. to the gallery 8, that is to'say adjacent the top of the lower hull part 2 of the body, and thence extending downward and inwardacross the longitudinal central plane of the hull, with their lower ends stepped in bearings 31 close to the bottom 13. The travelers 27 are formed as nuts to move up and down on the screws when the latter are rotated 1n one direction or the other. lIn the unfoldedor` operative.

position of the landing-gear they occupy positionsat the upper ends of thescrews, and from these positions are drawn downward and transversely to positions near. the bottom of the boat when the landing-gear is folded. In the foldedor retracted condition the members l 7 lie -transversely in the lower part of the gallery, entirely within thelines of the hull, and the members 6 are also substantially entirely rgceived within the gallery.`

The screws 30 are driven through means connected to their upper ends, said means including transverse shafts^32 having bevel pinions 33 at their outer ends meshing with bevel gears 34 on the/upper ends of the screw-shafts. The shafts 32 are driven by a reversible electric motpr 35, the means for ycontrolling which will be described.

When` the machine alights on its landingg'ear, heavy thrust is transmitted through the members 7, acting as thrust connections, to

-the nut travelers 27, and it is important to save these members and the screws 30 from injury. Lateral abutments 36 are accordingly provided for the nuts on the fixed framework 37 of the machine, adjacent the ,upper positions of the nuts, and means are provided for establishing a normal clearance or space 38 between the nuts and their abutments and for permitting the screws to yield harmlessly on alighting, so that the sides of the nuts bottom solidly on the abutments. The specific construction may be varied. In the illustrated ambodiment there is a bracket or tting 39 at each side of the hull, secured to the bulkheads 9, 10 and the transverse member 37, a flat` diagonal portion 36 of this bracket forming a facing over the beveled end of the member 37 constituting the abutment for the flat inner side, of the nut traveler. I

Each of the fittings also has a projecting bracket portion 40, which is carried transversely of the journal end 41 of the corresponding screw-shaft, this portion 40. having a somewhat elliptical hole 42. within which is the journal 41 and an encircling bearing bushing 43. F The bearing is thus capable of movement in the retaining bracket. the move- 'ment being lateral with respect to the screwshaft and upward and inward with respect to the hull. The bearing 43 is confined between the bevel gear 34 and a collar 44 pinned to the shaft, and a circumferential groove, to overlap the edge of the hole 42. is formed between a flange 45 of the bearing and a collar 46, so that the shaft and bearing are held against movement in the direction of the length of the shaft. The bearing and shaft, with the nut, are yieldingly pressed away from the abutment 36 by a stout spring .bar 47, the ends of which are received in openings in side portions of an extension 48 ofthe fitting, and the central portion of the spring, which is preferably bowed, bears against the backof a block 49. which lies in a slot 50 ofthe fitting and is bifurcated at its front or lower side to bear against flat faces on the ange 45 and the collar 46. The pressure from this spring is adjustable by a screw 51,` which is threaded through a hole in a lug 52 of the portion 48 of the fitting to bear against one end of the lUJ lill

spring. This spring normally holds the nut l dle 53 (Fig. 8), conveniently placed, and

connected by suitable mechanical connections 54, 55 withthe reversing switch 56 of the-motor and with the tiltable double blade 57 of an automatic cut-out 58. The motor drives the' shafts 32 through suitable reducing gearing 59, and the turning member 60 of the automatic cut-out is driven from the motor or shaftiiig through properly timedslow-motion gearing 61. The automatic cutout controls the motor circuit 72 through a relay 62, the circuit of which passes from the battery 63 through the coil of the relay by wire 64 to artiltable blade 65, which is properly insulated from the su port and from the turning member 60, and is normally held in central position by Springs 66. The driven turning member 60 `of the automatic cut-out carries-spaced tappets 67, 68, adapted to bear alternately against the blade 65 to shift the same in one direction or the other against the resistance of the springs. The manually-sliiftable double-blade element 57 of the cut-out is adapted to make `electrical contact at the ends of its limbs alternately with the blade 65. It issuitably insulated from the frame and connected by wires 69, 7() through an emergency switch 7l to ground. Tlie`wiring of a reversible electric motor, 'being well known, does not reqiire special explanation. p

i single movement of the control handle 53 in one direction or the other ycauses the landing-gear to be folded or unfolded, the motor being automatically cut out when the movement is complete. One movement of the control handle throws the reversing switch to set the circuits of the motor so that it will run in the direction to unfold the landing-gear. This movement also Swings the double blade 57 of the automatic cut-out,'so that one of its limbs makes electrical contact with the blade 65, thereby,

through tlierelay 62, closing the motor circuit. The motor then drives the screwshafts 30 to unfold the landing-gear, and also drives the slow-motion gearing 61 to turn thc member 60 of the cut-out, the timing beinfr such that, at the moment when the landing-gear is fully unfolded, one of the tappets 67, 68 presses against the blade 65, moving it away from the limb of the double blade 57 with which it was in contact. This breaks the relay circuit, and thereby breaks the motor circuit. Movenient of the handle 53 in the opposite direction throws the switch 56 to set` the motor circuit so that the motor will run in the direction to fold the landiiig-gear. It also rocks the double-blade member 57 so that its other limb makes contact with the blade 65, thereby' connecting the motor with the battery through the relay 62. The electrical driving action continues until the driven element 60 of the cut-out causes the other tappet to press against the blade 65, thereb moving it away from electrical contact wit the limb of the double blade 57, aga'n deenergizing the motor.

Returning to the wheels, the head 22 of each of the members 6 1s formed with spaced vertical guide opening, i'nwliieh spaced ver- 'tical`rods73. have sliding movement. These forni, since details may be varied and.

divers changes will suggest themselves to persons skilled in the art. The application is a continuation in part of my application filed November 8, .1923, Serial No. 673,407.

That I claim as new is:

1. A retractable landing gear havinga movable thrust connection, a `nut traveler to which said connection is pivoted, and a rotary operating screw, in combination with a spring-pressed yielding mounting for said j screw, and an abutment separated from the nut traveler in the projected position of the gear, to receive the thrust from the nut traveler when the screw yields harmlessly in its mounting on landing. i

2. In a retractable landing gear, the coinbination of a yieldingly mounted operating screw, a nut traveler on the screw whereby the landing gear is operated, and an abutment spaced from the nut traveler in the projected position of the landing gear to receive the thrust transmitted from the landing gear to the nut traveler on landing.

3. In a flying machine, a supporting structure, a retractable landing gear, a nut traveler to which said landing gear is connected, a rotary operating screw shaft for said nut traveler, a bearing for the screw sha'ft, a bracket on the supporting structure in which said bearing is laterally movable, an' `abutment on thesupporting structure to receive lateral thrust of the nut traveler on landing, and a spring pressing the bearing, shaft and nut away from the abutment. y

4. In a flying-boat, a hull having lateral sponsons and constructed with openwheel pockets extending from the upper sides of said sponsons downward into the hull and walled off from the buoyant interior of thi.l hull, and constructed also with transverse bulklieads .cut ilito by said pockets, and with an open transverse gallery between. said bulkheads, wheel-carrying landing-gear members pivoted to the hull at the chine corners of said sponsons to swing .laterallyv of the hull, upward and inward for folding the wheels downward into said pocket,

and outward and downward 'for.unfoldin`g, screw shafts mounted within the gallery between bulkheads in reverse' diagonal positions, means for rotating said screw shafts connected with their upper ends, nut travelers on said screw shafts, movable between positions on the upper portions of the shafts vbulkheads,

folded. j .v

7. In\a flying-boat, ahull having lateral which they occupy 1`n the unfolded condition ofthe landing gear and positions on the lower portions of the shafts which they occupy when the gear is folded, and link members connecting said travelers and the said apivoted members. h

5. In a dying-boat, a hull having lateral sponsons and constructed with open wheel pockets extending from the upper sides of said sponsons downward into the hull and walled off from the buoyant interior'of the hull, and constructed also with ytransverse bulkheadscut intoby said pockets, and with an open 'transverse gallery betw-'een said wheel-carrying landing-gear members pivoted on opposite sides of the hull to swing laterally of the hull upward and inward for folding the wheels down-l said sponsons downward into the hull and walled off from lthe buoyant interior of the hull, and constructed also with a transverse o ening extending inwardly of the sides of t 1e sponsons land intersecting the wheel pockets, and also. walledoif from the buoyant interior of the hull, wheel-carrying landing-gear'members pivoted on opposite sides of the hull to swing laterally of the hull, upward and inward 'for folding the/wheels downward intovsaid pockets, and outward' and downwardfor unfolding, operating devicesy mounted within said transverse opening of the hull, and members operatively connecting said pivoted members. with said operating devices so` as to be drawn inward and downward Iin said opening toward the bottom of the hullJwhen the landing gear is sponsons and constructed with wheel pockets extending from the upper sides of said sponsons into the hu'll and with a transverse opening intersecting said pockets and like them walled off from the buoyant interior .of the'hull, vlanding wheels, articulated linkages pivoted to the chine corners Bf the sponsons toswing laterally of thehull, up-

ward and inward for folding the wheels into` said pockets and outward and downward for unfolding, and operating means for said linkages arranged to draw 'the same inward and downward insaid opening toward the bottom of the hul-l when the landing gear is folded.

8. In a flying-boat, a hull having a bottom and an open space with wheel pockets in its sides above the bottom, landing wheels, articulated linkages pivoted on opposite sides of the hull, to swing upward and inward for folding said wheels into the wheel pockets, and outward and downward for unfolding,

and operating means .forsaid linkages ar` ranged to draw the linkages inward and downward of saidL1 open space toward saidv bottom .when the landing-gear is folded.

9. In a flying-boat, a hull, and a folding landing-gear including wheels, articulated linkages pivoted on opposite sides of the hull to swing laterally of the hull, upward and `inward for retracting said wheels, and outward and downward for projecting them, screw shafts mounted inI diagonal crossing relation within the lines of th hull, and nut travelers on said screw shafts with which said linkages are connected, said travelers `moving between positions on the 'upper portions of the screw shafts, which -they occupy when the landing-gear is unfolded, and posi.- tions on the lower portions of the shafts,

which they occupy when the landing-gear is folded. y y l0. In a fiying-boat, a hull, and a folding landing-gear including wheels, articulate linkages pivoted on opposite sides of the hull to swing laterally of the hull, upward and inward `for retracting said wheels, and outward and downward for projecting them, screw shafts mounted in reverse transverse diagonal positions within the lines of the hull, and nut travelers on said screw shafts with which said linkages are connected, said ltravelers moving between positions on the upper portions of the screw shafts, which they occupy when the landing-gear is unfolded, and positions on the lower portions of the shafts, which they occupy when the landing-gear is folded.

11. In a flying-boat, a hull, and a folding landing-gear including wheels, articulated linkages pivoted on opposite sides of the hull to swing laterally of the hull, upward and inward for retracting said wheels, and outward and downward for projecting them,

screw shafts mounted in reverselt-ransverse diagonal positions within the lines of the hull, nut travelers on said screw shafts jwith which said linkages are connected, said trav- Ielers moving between positions on the upper portions of the screw shafts, which they occupy when the landing-gear is unfolded, and

'positions on the lower portions of the shafts,

which. they occupy -when the landing-gear is folded, and means for rotating said shafts connected with the upper ends thereof.' i

12. In a flying-boat, a boat bodyand a folding landing gear including wheels, articulated linkages pivoted on opposite sides of the .body to swing laterally carrying said wheels upward and inward for folding, and downward and outward for unfolding, screw shafts mounted within the lines of the lower part of the lboat body, and nut travelers on said screw shafts with which said linkages are connected so that said linkages are drawn inwardly of said lower part of the boat body when thelanding gear is folded.

13. The combination in a flying machine, of a retractable landing-gear, gearing for operating the same, a reversible electric landing-gear motor connected to said gearing for' positively operating the landing-gear in both directions, a manual control'and an automatic cut-out for the motor circuit, said cut-out in driven relation with the landing- .20 gear, whereby a single control movement on the part of the pilot suiices for the projection or retraction of the landing-gear.

14. In a landing-gear, a wheel-carrying member, said member having spaced vertical guide openings in its head, a drum encircling said head and containing spaced vertical rods which slide in said guide openings, elastic means between said drum and member/and an outer wheel partrotatable on Said drum.

15. In a landing-gear, a wheel-carrying member, said member having spaced vertical guide openings in its head, a drum encircling said head and containing spaced vertical rods which slide in said guide openings, hor izontal bars mounted in said drum and in said end, respectively, elastic means wrapped about said horizontal bars, and an outer wheel part rotatable on said drum.

GROVER C. LOENING. 

